Introduction: The role of sentinel lymph node (SLN) mapping for breast cancer continues to evolve. Currently, the standard of care for patients who have a positive SLN is completion axillary lymph node dissection (ALND). For patients who elect to undergo immediate reconstruction, however, the SLN status on permanent histology may complicate management. If a metastasis is found that was not recognized on frozen section, the reconstructed patient may require re-operation to remove remaining axillary nodes. Some have suggested this re-operation may compromise the success of reconstruction.

The purpose of this study was thus to: i) determine the incidence of delayed, completion axillary dissection following concomitant mastectomy, sentinel lymph node biopsy and immediate reconstruction; and ii) determine the incidence of complications following completion axillary dissection in the newly reconstructed breast.

Methods: A retrospective review was performed. Patients who underwent immediate reconstruction following mastectomy and concomitant SLN from September 1996 to December 2004 were identified. Demographic, oncologic and reconstructive data was obtained from a prospectively-maintained, clinical database. Descriptive statistics were reported as a mean (range) and as a percentage of patients having the characteristic.

Results: From September 1996 to December 2004, 1557 patients had mastectomy and concurrent SLN biopsy followed by immediate, postmastectomy reconstruction (expander-implant reconstruction, n=1403 autogenous tissue reconstruction, n=154). Of these patients, 404 (25.9%) had a concomitant ALND; 1151 (74.1%) did not. Following review of permanent histology, 95 patients (8.3%) who did not have a concurrent ALND, were deemed to have a metastatic SLN requiring delayed, completion axillary dissection. Tissue expander/implant reconstruction had been initiated in 88 patients. Autogenous tissue reconstruction was performed in 7 patients: 5 patients had a free TRAM flap using the thoracodorsal artery vessels (n=4) and internal mammary vessels (n=1); 1 patient had pedicled latissimus flap; and, 1 patient had a pedicled TRAM flap. Mean patient age was 45.7 years (n=95; range, 23–77 yrs). Mean tumor size was 1.9 cm (n=79 invasive cancers; range, 1.9-6.0 cm). ALND was performed a mean 22.8 days following immediate reconstruction (range, 7-70 days). Mean number of axillary nodes excised at the time of completion ALND was 13.8 (1-29 nodes); mean number of positive axillary nodes was 1.3 (0-3 nodes). The overall rate of complications following immediate reconstruction and delayed, completion ALND was 2.1% (2/95). Infection (n=1) and expander exposure (n=1) resulted in premature expander removal in 2 patients. There were no partial or total flap failures. All patients successfully completed reconstruction.

Conclusions: This data suggests that mastectomy and concomitant SLN biopsy is a safe option for breast cancer patients undergoing immediate reconstruction. In well selected patients, completion axillary dissection can be safely performed in patients who have undergone immediate, implant and/or autogenous tissue reconstruction.